E PA/NJ/DE Winter 2025-26 Obs/Discussion

[ChescoWx]

We are seeing some lake effect streamers making into as far southeast as Chester County this morning and don't be surprised if we see a couple more snow showers during the day. We have already reached our high temperature for the day at about 130 this morning. Today’s temperatures will remain below freezing in most spots with wind gusts as high as 35 mph. Our top 10 coldest start to December looks like it will continue for at least the next week, and we may see a couple of snow chances over the next few days. The first one overnight Friday night looks very light while the next potential event toward Sunday morning could bring some locations their “largest” snow event this season. Of course, that would not be hard to do as our largest "event" has only been 0.5" Behind whatever happens on Sunday another very cold air mass moves in on Sunday night and lasts through Tuesday with temperatures from Sunday through Tuesday remaining in the mid to upper 20's for highs with lows in the teens.

[JTA66]

8 minutes ago, Mikeymac5306 said:

BTW I will not start a thread for Sunday morning. I'm saving up for the Wiggam storm to be

N'ah, the Wiggum storm is the Christmas Blizzard he promised us a few pages back. 

Just .20" yesterday. Currently 31F. Funny how it only got above freezing this week for a few hours when the precip arrived.

[Ralph Wiggum]

1 hour ago, Mikeymac5306 said:

Merry Torchmas! 

Im fine with this if it isnt going to be vodka cold or snowing. I can open the windows on Christmas and air out the stink that is my mother-in-law.

[Duca892]

If it ain't gonna snow give me a 60 degree Christmas Day 

[ChescoWx]

Little lake effect streamer with a little whitening here in NW Chester County 

[KamuSnow]

Just had some flurries here. Yay!

33F.

[Blue Dream]

9 minutes ago, Duca892 said:

If it ain't gonna snow give me a 60 degree Christmas Day 

That's fine...but I don't want dews in the 60s lol

[JTA66]

12k NAM at range doesn't suck for Sunday. But it's the 12K NAM at range, so... 

[ChescoWx]

[ChescoWx]

I think anyone expecting a Christmas "torch" will be unhappy. While it will of course get warmer - heck this is one of the coldest first half's of December since the 1890s. I don't see this like the 1989 pattern. I suspect Christmas week while a lot warmer than now...will be not too far above normal readings for Christmas IMHO.

[BBasile]

NAM and ECM both have rain for us south and east to start changing to snow.  2 inches is enough to cover the grass.  All I need.  

[ChescoWx]

From one of my favorite professionals Bobby Martrich at EPAWA on the upcoming milder but not torch pattern before cold returns.

"A lot of talk recently about a Christmas week "torch" and yes, there have and will be changes to the late next week period to just past Christmas that will take us out of the tank where we've been for much of December, and moderate the pattern. The culprit is a nearly 5 sigma high pressure/ridge over the Bering Sea, which was poorly modeled last week, and responded to a combination of a Scandinavian blocking pattern and the EAMT that retracted the Pacific jet too far... allowing this ridge to pop over the Bering Sea. If you watched the WW video last Sunday when I had

@ShaneMartrich

on, he talked about his research and lack of data in the polar regions. This may be one of those cases why the models and ensembles had a knee-jerk reaction this week. Kind of their version of an "oh crap" moment. By doing so, it turns the EPO positive, so the cross-polar flow is temporarily shut off. But for transparency, this is far from a "torch" pattern for us. Milder than now, yes... but aside from a synoptically-driven spike ahead of a cutter near the 18th, temperatures return closer to average instead of 15-20° below like they have been. This will be temporary, and may last more than a week, then colder returns late month and January."

[Ralph Wiggum]

RGEM is a nice swatch of 4-6". Nice to see things coming together rather than the opposite

[ChescoWx]

GFS did move north a bit from it's 6z run...but still south of some of the other models. 

[Ralph Wiggum]

48 minutes ago, ChescoWx said:

GFS did move north a bit from it's 6z run...but still south of some of the other models. 

GFS is always the last to nudge North

[Kevin Reilly]

4 hours ago, ChescoWx said:

We are seeing some lake effect streamers making into as far southeast as Chester County this morning and don't be surprised if we see a couple more snow showers during the day. We have already reached our high temperature for the day at about 130 this morning. Today’s temperatures will remain below freezing in most spots with wind gusts as high as 35 mph. Our top 10 coldest start to December looks like it will continue for at least the next week, and we may see a couple of snow chances over the next few days. The first one overnight Friday night looks very light while the next potential event toward Sunday morning could bring some locations their “largest” snow event this season. Of course, that would not be hard to do as our largest "event" has only been 0.5" Behind whatever happens on Sunday another very cold air mass moves in on Sunday night and lasts through Tuesday with temperatures from Sunday through Tuesday remaining in the mid to upper 20's for highs with lows in the teens.

Coating made it all the way to Media 9-9:30 am. 

[Kevin Reilly]

3 hours ago, ChescoWx said:

Way way north of other models cha cha cha lol

[Kevin Reilly]

52 minutes ago, Ralph Wiggum said:

GFS is always the last to nudge North

Model bounce has begun Euro up big runs tonight! I’ll say 3-4” or do max 5” isolated areas. 

[Newman]

Euro has been largely consistent in showing a general 2-4" for much of the Philly metro the past few runs with upwards of 5" in localized spots. Berks, Lehigh, Northampton probably 1-3" but this is one of those setups where you can get a strong fronto band on the NW side of the precip shield as the upper level jet shifts towards the area under the favorable right entrance region. I think the precip shield would actually expand a bit further northwest than what the Euro shows with isentropic glide along the frontal boundary as the TPV drops in from the south.

However, that same TPV is pushing everything along and out to sea so it's a fine balance between the flow buckling and getting that precip shield to expand vs everything shunted east. Will have to watch the trends with the models, have to get a bit greater height rises ahead of this one